Laparoscopic minimally invasive surgery has been rapidly developing. During this type of surgery, internal body parts may be viewed via an endoscopic camera attached to a laparoscope with the image transmitted to a monitor screen. Entry into the abdomen (and other body sites) is generally obtained via devices known as laparoscopic trocars. FIGS. 1 and 2 illustrate an example of a conventional laparoscopic trocar 100. Trocar 100 may include a cylindrical sleeve 102 having an open distal end 118. Sleeve 102 may provide a route for accessing a body cavity through a small incision. Sleeve 102 may also provide a passage for carbon dioxide gas to be pumped into the body cavity to distend the body cavity, providing better visibility within the body cavity.
An obturator 106 may be used with trocar 100 to insert trocar 100 into the body cavity. Obturator 106 may include a tube 120 having a pointed tip 110 at a distal end. Pointed tip 110 may include a first separator 114 and a second separator 116. An obturator main body 108 may be attached to obturator 106 at a proximal end. Trocar 100 may include a trocar main body 112 attached to a proximal end of sleeve 102. As shown in FIG. 2, obturator 106 may be assembled with trocar 100 by inserting tube 120 through trocar main body 112 into sleeve 102. Pointed tip 110 may protrude through the distal end of sleeve 102. Assembled together, obturator 106 and trocar 100 may be inserted into a body cavity through an incision made by a scalpel. Pointed tip 110 may penetrate through tissue as obturator 106 and trocar 100 are pushed and twisted into the body cavity. First separator 114 and second separator 116 may help separate tissue as obturator 106 and trocar 100 are pressed into the body cavity. Once trocar 100 is in place, obturator 106 may be removed from trocar 100 so that surgical instruments may be introduced into the body cavity through sleeve 102.
If trocar 100 is accidentally dislodged from its placement site surgical instruments cannot be placed into the body cavity. Dislodgement slows down the operative procedure while the surgeon struggles to return trocar 100 to the body cavity. Furthermore, in the event of dislodgment, the carbon dioxide gas used to distend the body cavity during such procedures dissects into the subcutaneous tissue spaces because trocar 100 is no longer preventing same. Due to all of these problems, avoidance of trocar displacement is a critical aspect of successful laparoscopic surgery. To help prevent trocar displacement, the outer surface of sleeve 102 may include ridges 104. Ridges 104 are intended to help retain trocar 100 within the incision by friction between the body wall tissues and ridges 104. However, this amount of friction does not always prevent trocar 100 from dislocating itself or slipping out from the body. For example, when a surgical instrument is quickly removed from trocar 100 during an emergency, the surgical instrument may be removed with the distal end of the instrument inadvertently left in a position that causes the distal end to not fit through sleeve 102. In this position, the distal end of the instrument may press against the distal end of sleeve 102 forcing sleeve 102 to be displaced. Because of the problems associated with trocar displacement, it would be advantageous for a system and method for preventing trocar displacement.